Let's get this out of the way: Cool. Dam. Bridge.
But really, Hoover Dam and this bridge exist in symarchitectonis (it's a word now). How did people fully enjoy the Hoover Dam before this bridge was created? The bridge provides a perfect view of the dam and relieves the traffic that allows for a leisurely drive across. The dam and provides a perfect view of the bridge, which is impressive in its own right.
A little more to ponder on - both the bridge and the dam are the fruit of American tragedy. The dam is a product of the Great Depression, an FDR project to provide jobs and save the economy, and the bridge is a product of 9/11, a Bush project to protect the Hoover Dam from terrorism. Makes me wonder if we'd ever get around to doing anything impressive at all without threats to our imminent survival to motivate us.
Definitely worth a stop and a gape.